Miscellaneous - Sounds Wild
Elevational Migrations


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Elevational migrations

The seasonal migrations of waterfowl are well known. When geese that nest in Alaska fly south to Oregon for the winter, it's a latitudinal migration, from high or northern latitudes to low or southern latitudes. Some animals do a different kind of seasonal migration in the fall, to warmer locations, but they don't move thousands of miles. These birds and animals do elevational migrations, and move from high elevations to lower elevations.

In spring and summer, ptarmigan nest and feed in alpine areas and in the upper reaches of timber. In early fall they move downslope and seek food and shelter at lower elevations. In most parts of Alaska these movements between summer and winter ranges encompass just a few miles.

Generally speaking, a 1,000 foot descent in elevation equals a temperature change of about three-and-a-half degrees Fahrenheit. So a ptarmigan that moves from 3,500 feet to 1,500 feet will experience temperatures that are on average seven degrees warmer. In addition, winds are usually milder at lower elevations. The ptarmigan's descent of 2,000 feet may require a short flight, but it is equivalent to a migration southward of several hundred miles.

The American dipper, a familiar streamside songbird, does not migrate south but will move down to lower elevations in winter. Mountain goats and Sitka black-tailed deer also make seasonal migrations to lower elevation, returning to the high country in the spring and summer.